TWI757288B - Solid state microwave heating apparatus with dielectric resonator antenna array, and methods of operation and manufacture - Google Patents

Abstract

An embodiment of a microwave heating apparatus includes a solid state microwave energy source, a chamber, a dielectric resonator antenna with an exciter dielectric resonator and a feed structure, and one or more additional dielectric resonators each positioned within a distance of the exciter resonator to form a dielectric resonator antenna array. The distance is selected so that each additional resonator is closely capacitively coupled with the exciter resonator. The feed structure receives an excitation signal from the microwave energy source. The exciter resonator is configured to produce a first electric field in response to the excitation signal, and the first electric field may directly impinge on the additional resonator(s). Impingement of the first electric field may cause each of the additional resonators to produce a second electric field. The electric fields are directed into the chamber to increase the thermal energy of a load within the chamber.

Description

Solid State Microwave Heating Device with Dielectric Resonator Antenna Array and Methods of Its Operation and Fabrication

Field of Invention

Embodiments of the subject matter described herein relate generally to solid state microwave heating devices and methods of operation and manufacture of the same.

Background of the Invention

For many years, magnetrons have been commonly used in microwave ovens to generate microwave energy for the purpose of heating food, beverages, or other items. A magnetron consists essentially of a circular chamber with a plurality of cylindrical chambers spaced around its edges, a cathode built into the center of the chamber, and a magnet configured to generate a magnetic field when incorporated into a microwave system , the cathode is coupled to a direct current (DC) power supply configured to provide a high voltage potential to the cathode. The magnetic field and cylindrical chamber generate electrons within the chamber to induce a resonant, high frequency radio frequency (RF) field in the chamber, and a portion of the field can be extracted from the chamber by a probe. A waveguide coupled to the probe guides the RF energy to the load. For example, in a microwave oven, the load may be a heating chamber whose impedance may be to be affected by objects in the heating chamber.

While magnetrons work well in microwave and other applications, they are not without their own drawbacks. For example, magnetrons typically require very high voltages to operate. Furthermore, magnetrons may be susceptible to output power degradation over extended operating periods. Consequently, the performance of a system including a magnetron may degrade over time. Additionally, magnetrons tend to be bulky and heavy components that are sensitive to vibration, thus making them unsuitable for use in portable applications.

According to an embodiment of the present invention, a microwave heating device is specially proposed, which is characterized by comprising: a solid-state microwave energy source; a first dielectric resonator antenna, which includes a first exciter dielectric resonator and a A first feed structure of an exciter dielectric resonator, wherein the first exciter dielectric resonator has a top surface and an opposing bottom surface, wherein the first feed structure is electrically coupled to the source of microwave energy to remove a first excitation signal is received in the microwave energy source, and wherein the first exciter dielectric resonator is configured to generate a first electric field in response to the excitation signal provided to the first feed structure; and one or A plurality of second dielectric resonators placed within a distance of the first exciter dielectric resonator to form a dielectric resonator antenna array, wherein the distance is selected such that when the excitation signal is provided the first exciter Each of the two dielectric resonators is tightly capacitively coupled to the first exciter dielectric resonator.

100, 300, 900, 2400: microwave heating equipment; microwave systems

110, 910, 2410: Shell

112, 912, 1012, 1112, 2412: base part

114, 914, 2414: Chamber section

116, 916, 2416: Lid

118: External port

120, 320, 920, 2420: Heating chamber

122, 922: inner wall

130: Control Panel

140, 940, 2440: load

200, 1000, 1100, 1900: microwave heating equipment

310: System Controller

330: User Interface

340: Power Supply System; Heating Chamber; Power Supply; Power Supply System

350, 950, 1050, 1150, 2450, 2452: Modules

352: Solid State Oscillator Subsystem

354: Frequency Tuning Circuit

356: Bias circuit

358: Amplifier output node

360, 1060, 1160, 1200, 1300, 1400, 1500, 1600, 1700: DRA arrays

370: Feeding Structure

400, 510, 520, 1800, 1900, 2000, 2100, 2200, 2300: Dielectric resonators

410: Top Surface

412: Bottom Surface

416: External Sidewall

420, 512: center hole

422: Internal Sidewall

430: height

432: Diameter

440: Circumferential Electron Field

442: Orthogonal Electron Field, Electron Field

450: Inertial Coordinate System

500: DRA array, DRA antenna

530, 1330, 1640: Substrate

540: Distance

550, 968, 1250, 1260, 1350, 1352, 1550: Feed

560, 1260, 1360, 1460, 1560, 1174, 1176: Microstrip lines

700: Circuit Diagram

710: First Resonant Circuit

720: Second Adjacent Resonant Circuit, Second Resonant Circuit

730: Third Adjacent Resonant Circuit, Third Resonant Circuit

740: Capacitor

924: Chamber Bottom Surface

926: Chamber top surface

952, 1152: Power transistor

954: Conductive Transmission Lines

960, 2460: first DRA array; DRA array

962, 2462: Second DRA array; DRA array

964, 1210, 1310-1313, 1410-1412, 1512, 1520, 1522, 1610, 1620, 1630,: dielectric resonators; exciter resonators

966, 1320, 1420: Dielectric Resonators; Parasitic Resonators

970, 1070, 1170, 1170, 2470, 2472: Electronic substrates

972, 1072, 1172: Ground plane

980, 1080: DRA array substrate

982: Cover

990: Shaded Area

1064, 1164: Exciter Resonator

1066, 1166: Parasitic resonators

1082: Conformal Coating

1174: Pore

1220: Dielectric Resonators; Parasitic Dielectric Resonators; Parasitic Resonators

1640: Upper Surface

1710: Resonator; Dielectric Resonator; First Dielectric Resonator

1720: Resonator; Dielectric Resonator; Second Dielectric Resonator

1730: Resonators; Dielectric Resonators; Third Dielectric Resonators

2412: Block part

2420: Chamber

2502-2508, 2602-2608: Blocks

The detailed description is by reference when considered in conjunction with the following figures A more thorough understanding of the subject matter can be obtained in the claims, wherein like reference numerals refer to like elements throughout the various figures.

1 and 2 are perspective views of a portable microwave heating apparatus in an open state and a closed state, respectively, according to an example embodiment; FIG. 3 is a diagram including a microwave power generation module and a dielectric resonator antenna according to an example embodiment A simplified block diagram of a microwave heating apparatus for a (DRA) array; FIG. 4 is a perspective view of a dielectric resonator; FIGS. 5 and 6 are top and perspective views of a DRA array according to example embodiments; A circuit diagram of the electronic characteristics of a DRA with three adjacent dielectric resonators of an embodiment; FIG. 8 is a graph depicting the gain bandwidth of a DRA array according to an embodiment; FIG. 9 is a diagram of FIGS. 1 and 2 according to an example embodiment. sectional side view of a portable microwave heating device; FIG. 10 is a sectional side view of a portion of a portable microwave heating device according to another example embodiment; FIG. 11 is a portable microwave heating device according to a further example embodiment 12 is a top view of a DRA array suitable for use in a microwave heating apparatus according to another example embodiment; FIG. 13 is a top view of a DRA array suitable for use in a microwave heating apparatus according to another example embodiment ; 14 is a top view of a DRA array suitable for use in a microwave heating apparatus according to another example embodiment; FIG. 15 is a top view of a DRA array suitable for use in a microwave heating apparatus according to yet another example embodiment; FIG. 16 is according to yet another example embodiment A perspective view of a DRA array suitable for use in a microwave heating apparatus of an example embodiment; FIG. 17 is a perspective view of a DRA array suitable for use in a microwave heating apparatus according to yet another example embodiment; FIGS. 18-23 are of various shapes A perspective view of a dielectric resonator; FIG. 24 is a cross-sectional side view of a portable microwave heating device according to another example embodiment; FIG. 25 is a flowchart of a method of operating a microwave system including a DRA array according to an example embodiment; And FIG. 26 is a flowchart of a method of fabricating a microwave system including a DRA array according to an example embodiment.

Detailed ways

The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the words "exemplary" and "example" mean "serving as an example, instance, or illustration." Any embodiment described herein as illustrative or example should not necessarily be construed as preferred or advantageous over other embodiments. Furthermore, there is no intention to be bound by any presentation of the preceding technical field, background or the following detailed description A limitation of the theory expressed or implied.

Embodiments of the subject matter described herein relate to solid state microwave heating devices (eg, stationary or portable microwave ovens, microwave defrosters, etc.), although various embodiments may also be used in other systems. As described in more detail below, an exemplary microwave heating apparatus is implemented using a microwave generating module, a dielectric resonator antenna (DRA) array, and a chamber. The microwave generating module provides radio frequency energy to the DRA array, and the DRA array radiates the energy into a chamber in which a load (eg, a food load or some other type of load) can be placed.

As used herein, the term "dielectric resonator" refers to an object composed of a bulk dielectric material (eg, ceramic) capable of receiving radio frequency energy and in one or more resonant modes at the resonant frequency of the dielectric resonator Resonant RF energy. The resonant frequency is determined by the shape and size of the dielectric material and the dielectric constant of the bulk dielectric material. Generally speaking, dielectric resonators are characterized as having relatively high dielectric constants and relatively high Q-factors. According to various embodiments, several types of resonant modes can be excited in a dielectric resonator.

As used herein, the term "dielectric resonator antenna" or "DRA" refers to an antenna assembly that includes a dielectric resonator and one or more radio frequency signal feeds. The radio frequency signal feed is configured to carry the radio frequency signal and is positioned relative to the dielectric resonator such that the radio frequency signal excites the dielectric resonator and causes the dielectric resonator to resonate radio frequency energy in a resonant mode at the resonant frequency of the dielectric resonator. The resonant characteristics of the DRA depend on the shape and size of the dielectric resonator and on the shape, size and location of the feed. as described herein In use, a dielectric resonator that is excited directly from a feed by a radio frequency signal is referred to as an "exciter dielectric resonator". Ideally, the radio frequency signal is an oscillating signal having a frequency at or near the resonant frequency of the exciter dielectric resonator.

According to several embodiments, a DRA includes a dielectric resonator with one or more metallic monopole probes (ie, feeds) inserted into a dielectric material. The presence of a ground plane on one side of the DRA causes the DRA to radiate power primarily in the "forward" direction (eg, into the heating chamber adjacent to the DRA). In an alternative embodiment, the DRA includes a dielectric resonator disposed on or near a grounded substrate, the grounded substrate having energy transferred to the dielectric resonator by means of a monopolar aperture feed provided in the grounded substrate. It is also possible to connect directly to the microstrip transmission line and to excite via the microstrip transmission line.

As used herein, the terms "dielectric resonator antenna array" and "DRA array" refer to an assembly that includes at least one DRA and at least one additional dielectric resonator tightly capacitively coupled to the DRA. In one embodiment, the dielectric resonator of the DRA and the additional dielectric resonator are arranged in a coplanar configuration. In other words, the DRA array includes a plurality of closely capacitively coupled dielectric resonators and one or more feeds that are in or near many of the one or more of the plurality of dielectric resonators one or more of the dielectric resonators to form one or more DRAs in the array.

According to one embodiment, the DRA's dielectric resonator is referred to as an "exciter resonator" because it is configured to directly excite and induce resonance through a signal carried on the feed (ie, it directly receives electrical power from the feed). magnetic energy). In contrast, one or more of the dielectric resonators in a DRA array may be a "parasitic resonator" in that it does not receive electromagnetic energy directly from the feed. In such embodiments, the one or more exciter resonators and the one or more parasitic resonators of the DRA are arranged such that capacitive coupling occurs between the dielectric resonators of the DRA, or more specifically, the DRA between the exciter resonator and the parasitic resonator. In other words, the parasitic resonators are arranged such that the electric field generated by the exciter resonator (referred to as the "exciter-generated electric field") directly impinges on one or more parasitic resonators, which causes the parasitic resonators to also resonate . In other words, the parasitic resonator then generates a "parasitic generated electric field" as the electric field generated by the exciter impinges on the parasitic resonator. The dielectric resonators in the DRA array are arranged such that the exciter-generated electric field and the parasitic-generated electric field are each primarily directed in substantially the same direction. In one embodiment of the microwave heating device, the exciter-generated electric field and the parasitic-generated electric field are each primarily directed in the direction of a heating chamber of the microwave heating device, wherein the chamber is configured to contain the load to be heated (eg, food load). As used herein, the term "heating" and its various derivatives refer to increasing the thermal energy of a substance. While such an increase in thermal energy (or "heating") can raise the temperature of the substance to temperatures significantly above ambient, "heating" can also involve raising the temperature of the substance by any amount (eg, thawing the substance to cool it down) temperature rises from minus to ambient).

As will be discussed in more detail below, embodiments of the DRA arrays disclosed herein constitute relatively broadband structures that efficiently couple radio frequency energy from the microwave generating module into the load within the heating chamber. When compared to conventional antennas for microwave heating applications, embodiments of DRA arrays are very insensitive to near-field loads (eg, due to loads placed within the chamber) due to the wide bandwidth.

1 and 2 are perspective views of the portable microwave heating apparatus 100 in an open state and a closed state, respectively, according to an example embodiment. Microwave heating apparatus 100 includes housing 110, heating chamber 120, control panel 130, one or more microwave power generating modules (eg, module 350, FIG. 3), one or more DRA arrays (eg, DRA array 500, 5) and other components discussed in more detail below.

In one embodiment, the housing 110 includes a base portion 112 , a chamber portion 114 and a lid 116 . In one embodiment, the base portion 112 may contain a microwave power generation module and at least one DRA array. Additionally, the base portion 112 may contain a power supply system, such as a rechargeable battery system or a non-rechargeable battery system that powers the microwave power generation module and control panel 130 . When the external port 118 is coupled to a corresponding cable (not shown), the external interface 118 may be used to receive power to operate the device 100 and/or to recharge the rechargeable battery system of the device 100 . Additionally, the external port 118 may be used to communicate with external systems to receive, for example, software updates.

Heating chamber 120 is located within chamber portion 114 of housing 110 and is defined by inner sidewall 122, a chamber bottom surface (eg, surface 924, FIG. 9), and a chamber top surface (eg, surface 926, FIG. 9). As shown in FIG. 1 , when lid 116 is opened, heating chamber 120 may be accessed and a load 140 (eg, a food load or other negative load) may be placed within chamber 120 load). As shown in FIG. 2, when the lid 116 is closed, the heating chamber 120 becomes a closed air chamber, which essentially acts as a waveguide with closed ends. According to one embodiment, the microwave generating module is deactivated when the lid 116 is opened, and the microwave generating module can be activated only when the lid 116 is closed. Accordingly, microwave heating device 100 may include a sensor or other mechanism for detecting the state (ie, open or closed) of lid 116 .

To operate microwave heating device 100, a user may open lid 116, place one or more objects (eg, load 140) into heating chamber 120, close lid 116, and by specifying desired heating duration and desired power level The control panel 130 provides input. In response, a system controller (eg, controller 310, Figure 3) causes a microwave power generation module (eg, module 350, Figure 3) to provide excitation signals to a DRA array (eg, DRA array 360, Figure 3). In response, the DRA array radiates electromagnetic energy in the microwave spectrum (referred to herein as "microwave energy") into the heating chamber 120 . More specifically, the system controller causes the microwave power generation module to cause the DRA array to radiate microwave energy into the heating chamber 120 for a period of time at a power level consistent with the user input. The microwave energy increases the thermal energy of the load 140 (ie, the microwave energy causes the load to heat up).

Each DRA array is configured to radiate microwave energy into the heating chamber 120 . In one embodiment, the radiant energy has wavelengths in the microwave spectrum that are particularly suitable for heating liquids and solid objects (eg, liquids and food). For example, each DRA array may be configured to radiate microwave energy having a frequency in the range of about 2.0 gigahertz (GHz) to about 3.0 GHz into the heating chamber 120 . More specifically That said, in one embodiment, each DRA array may be configured to radiate microwave energy having a wavelength of about 2.45 GHz into the heating chamber 120 .

As will be described in further detail below, each microwave power generation module may be implemented as an integrated "solid state" module in which each microwave power generation module includes a solid state circuit configuration that generates and radiates microwave energy (while not including the magnetron). Thus, when compared to conventional magnetron-based microwave systems, embodiments of the system, including embodiments of microwave power generation modules, may operate at relatively lower voltages, may be less susceptible to output over time The effects of power degradation and/or may be relatively compact.

Although microwave heating apparatus 100 is shown with its components in a particular relative orientation relative to one another, it should be understood that the various components may be oriented differently. Additionally, the physical configuration of the various components may vary. For example, the control panel 130 may have more, fewer, or different user interface components, and/or the user interface components may be arranged differently. Alternatively, the control panel 130 may be located within the base portion 112 or the lid portion 116 of the device 100 . Furthermore, although generally cylindrical apparatus 100 and heating chamber 120 are shown in FIG. 1 , it should be understood that the heating chamber may have different shapes (eg, rectangular, elliptical, etc.) in other embodiments. Additionally, microwave heating apparatus 100 may include additional components not specifically depicted in FIG. 1 . Still further, although embodiments of "portable" microwave heating devices are shown and described in detail herein, those skilled in the art will appreciate that the inventive embodiments of DRA arrays are also applicable to stationary microwave heating devices ( For example, large equipment and/or equipment powered by an external power supply network (or grid).

FIG. 3 is an example of including one or more DRAs according to an example embodiment. Simplified block diagram of microwave heating apparatus 300 of array 360 (eg, microwave heating apparatus 100 , FIG. 1 ). Additionally, the microwave system 300 includes a system controller 310 , a user interface 330 , a power supply 340 , a heating chamber 320 and one or more microwave power generating modules 350 . It should be understood that FIG. 3 is a simplified representation of microwave system 300 for purposes of explanation and ease of description, and that actual embodiments thereof may include other devices and components to provide additional functions and features, and/or microwave system 300 may be a large power system part.

User interface 330 may correspond to a control panel (eg, control panel 130, FIG. 1 ) that, for example, enables a user to set parameters related to a heating operation (eg, duration of heating operation, duration of heating operation, Power levels, codes associated with specific heating operating parameters, etc.) are provided to the system, start and cancel buttons, and the like. Additionally, the user interface may be configured to provide user-perceivable outputs (eg, countdown timers, audible tones indicating completion of the heating operation, etc.) and other information indicating the status of the heating operation.

System controller 310 is coupled to user interface 330 and to power supply system 340 . For example, system controller 310 may include one or more general-purpose or special-purpose processors (eg, microprocessors, microcontrollers, application-specific integrated circuits (ASICs), etc.), volatile and/or non-volatile non-volatile memory (eg, random access memory (RAM), read only memory (ROM), flash memory, various registers, etc.), one or more communication buses, and other components. According to one embodiment, the system controller 310 is configured to receive a signal indicative of a user input received through the user interface 330, and for a duration and at a time corresponding to the received user input The input power level causes the power supply 340 to provide energy to the microwave power generation module 350 .

The power supply 340 may selectively provide a power supply voltage to each microwave power generation module 350 according to a control signal received from the system controller 310 . When each microwave power generation module 350 is supplied with the appropriate supply voltage from the power supply 340 , each microwave power generation module 350 will generate a radio frequency signal that is transmitted to one or more of the parts forming part of the DRA array 360 or A plurality of feed structures 370 (or "feeds"). In response, DRA array 360 radiates microwave energy into heating chamber 320 . As mentioned previously, the heating chamber 320 essentially acts as a waveguide with closed ends. The dielectric resonators of DRA array 360 , heating chamber 320 , and any loads placed in heating chamber 320 (eg, load 140 , FIG. 1 ) correspond to cumulative loads of microwave energy generated by DRA array 360 . More specifically, the dielectric resonator, the heating chamber 320 and the load within the heating chamber 340 present impedance to the microwave power generating module 350 .

According to one embodiment, each microwave power generation module 350 may include a solid state oscillator subsystem 352 , a frequency tuning circuit 354 and a bias circuit 356 . According to one embodiment, oscillator subsystem 352 includes a solid state amplifier (eg, including one or more power transistors) and a resonant circuit. In various embodiments, the power amplifier within oscillator subsystem 352 may include a single-ended amplifier, a double-ended amplifier, a push-pull amplifier, a Doherty amplifier, a switch mode power amplifier (SMPA), or another type of amplifier.

In an embodiment, oscillator subsystem 352 is a power microwave an oscillator in which elements of oscillator subsystem 352 are configured to generate an oscillating electrical signal at output node 358, wherein the signal has frequencies in the microwave spectrum having relatively high output power (eg, output power in the range of about 100 watts (W) to about 300 W or higher). A resonant circuit coupled along a feedback path between the output and input of the power amplifier completes a resonant feedback loop that causes the amplified electrical signal produced by the power amplifier to be at or near the resonance frequency of the resonant circuit frequency oscillation. In an embodiment, the resonant circuit is configured to resonate at a frequency in the microwave spectrum (eg, at a frequency of about 2.45 GHz). The amplified electrical signal produced by the amplifier arrangement oscillates at approximately the resonant frequency of the resonant circuit. It should be noted that, in practice, embodiments of the resonant circuit may be configured to resonate at different frequencies to suit the needs of the particular application in which microwave system 300 is used.

According to one embodiment, the power amplifier is implemented as a single-stage transistor or a multi-stage transistor having an input (or control) coupled to the tuning circuit 354 and an output (eg, a control) coupled to the amplifier output node 358 . , the drain terminal). For example, the transistor may comprise a field effect transistor (FET) having a gate terminal connected to tuning circuit 354, a drain terminal connected to amplifier output node 358, and a ground reference voltage (eg, about 0 volts, although in some embodiments the ground reference voltage may be higher or lower than the source terminal of 0 volts). For example, the transistors may include laterally diffused metal oxide semiconductor FET (LDMOSFET) transistors. It should be noted, however, that transistors are not intended to be limited to any particular semiconductor technology, and in other embodiments, transistors are The bulk can be implemented as a gallium nitride (GaN) transistor, another type of MOSFET transistor, a bipolar junction transistor (BJT), or a transistor using other semiconductor technologies.

Frequency tuning circuit 354 includes capacitive elements, inductive elements, and/or resistive elements configured to adjust the oscillation frequency of the oscillating electrical signal generated by oscillator subsystem 352 . In the exemplary embodiment, frequency tuning circuit 354 is coupled between the ground reference voltage and the input of oscillator subsystem 352 .

Bias circuit 356 is coupled between power supply 340 and oscillator subsystem 352 and is configured to receive a positive (or supply) voltage from power supply 340 . According to one embodiment, the bias circuit 356 is configured to control a direct current (DC) or nominal bias voltage at the gate and/or drain terminals of the transistors within the oscillator subsystem 352 in order to turn on the transistors and at the The transistor is maintained to operate in an active mode during operation of the oscillator subsystem 352 . Although not shown, the bias circuit 356 may also include a temperature sensor and a temperature compensation circuit configured to sense or detect the temperature of the transistor and be responsive to an increase in the temperature of the transistor and /or lower to adjust the gate bias voltage. In such embodiments, the bias circuit 356 may be configured to maintain a substantially constant quiescent current of the transistor in response to temperature changes.

Oscillator subsystem 352 is coupled to feed structure 370 through one or more impedance matching circuits (not shown). As will be explained in greater detail below, embodiments of feed structures 370 include conductive structures placed within one or more dielectric resonators of one or more DRA arrays 360 . for Instead, feed structure 370 may include microstrip lines that are apertured coupled to one or more dielectric resonators of one or more DRA arrays 360 .

DRA array 360 is configured to radiate microwave energy into heating chamber 320 . More specifically, at oscillator output node 358, feed structure 370 and DRA array 360 convert the oscillating electrical signal into an electromagnetic microwave signal. For example, in a microwave heating device application where oscillator subsystem 352 is configured to generate a signal at a frequency of about 2.45 GHz, at oscillator output node 358, DRA array 360 converts the oscillating electrical signal to a frequency at 2.45 GHz The microwave electromagnetic signal at and direct the microwave signal into the heating chamber 320 of the microwave heating device 300 .

When microwave heating apparatus 300 includes multiple DRA arrays 360, DRA arrays 360 may be configured to resonate at the same frequency and power level, and may operate simultaneously or in a defined sequence. Alternatively, the DRA arrays 360 may be configured differently (eg, they may resonate at different frequencies, and/or may radiate microwave energy at different power levels). In such alternative embodiments, the DRA arrays 360 may operate concurrently or in a defined order.

As will be depicted in more detail in FIGS. 5-7 and 9-17, each DRA array includes a plurality of dielectric resonators arranged such that at least one parasitic resonator is tightly capacitively coupled with at least one exciter resonator device. Before discussing various embodiments of a DRA array in detail, an embodiment of the basic building block of a DRA array, or more specifically an embodiment of a dielectric resonator, will be discussed in conjunction with FIG. 4 .

FIG. 4 is a perspective view of a dielectric resonator 400 suitable for use in one embodiment of a DRA array. Dielectric resonator 400 is formed from bulk dielectric materials, eg, ceramics, _{perovskite compounds} (eg, incorporating Nd2O3, _TiO2 , CaO/SrO, BaO, MgO, ZnO, _CoO , _Ta2O5 and/or Nb ₂ O ₅ etc.) or other suitable materials. According to one embodiment, the bulk dielectric material has a relatively high dielectric constant, such as a dielectric constant between about 8 and about 70, although the dielectric constant may also be greater or less. Additionally, in one embodiment, the bulk dielectric material has a relatively high quality factor (Q), such as an unloaded Q of between about 40,000 and about 300,000, although the bulk dielectric material may also have lower or Higher no-load Q. Still further, in one embodiment, the bulk dielectric material has a very low coefficient of thermal expansion (eg, about 0 ppm).

In the illustrated embodiment, the dielectric resonator 400 has a cylindrical shape with a top surface 410 , a bottom surface 412 , and an outer sidewall 416 extending between the top surface 410 and the bottom surface 412 . Additionally, dielectric resonator 400 has a central channel or hole 420 extending between top surface 410 and bottom surface 412 , wherein central hole 420 is defined by interior sidewalls 422 . As will be discussed in more detail later in conjunction with Figures 18-23, dielectric resonators having a variety of other shapes may be used in various other embodiments of DRA arrays.

The illustrated dielectric resonator 400 can be used as an exciter resonator or a parasitic resonator in a DRA array. When used as an exciter resonator, a conductive feed (eg, feed 550, FIG. 5 ) can be inserted into the center hole 420 from the bottom surface 412 of the dielectric resonator 400 and provided to the feed The transmitted radio frequency signal can be used to cause the dielectric resonator 400 to resonate at the characteristic resonance frequency of the dielectric resonator 400 . For example, the resonant frequency can be in the range of about 2.0 GHz to about 3.0 GHz, although the resonant frequency can also be lower or higher. The resonant frequency of dielectric resonator 400 is defined, at least in part, by the dielectric constant of the bulk dielectric material and the shape and size of dielectric resonator 400 (eg, height 430 and diameter 432). In general, the higher the dielectric constant, the smaller the dielectric resonator can be for a given resonant frequency. Furthermore, for any given dielectric constant and dielectric resonator shape, smaller dielectric resonators resonate at higher resonant frequencies than larger dielectric resonators.

In the embodiment shown in FIG. 4, the dielectric resonator 400 has a circular cross-sectional area. Thus, when a radio frequency signal is used to excite dielectric resonator 400, a circumferential electron field 440 (referred to herein as the "primary" electric field) is generated through dielectric resonator 400. In addition, a vertical or secondary electron field 442 (ie, electron field 442 orthogonal to top surface 410 and/or bottom surface 412) is also generated when the feed placed in dielectric resonator 400 carries a suitable radio frequency signal. The strength of the secondary or orthogonal electron field 442 may depend, at least in part, on the distance the feed extends into the central aperture 420 . Either way, when properly excited by the radio frequency signal carried by the feed, the dielectric resonator 400 can produce three polarizations in orthogonal axes relative to the inertial coordinate system (eg, the fixed inertial coordinate system 450 Magnetic energy field directed in orthogonal axes "X", "Y" and "Z").

As mentioned above, a DRA array suitable for use in microwave heating devices (eg, microwave heating devices 100, 200, Figures 1, 2) may include an arrangement such that at least one parasitic resonator and at least one exciter The resonators are multiple dielectric resonators that are tightly capacitively coupled (eg, multiple instances of dielectric resonator 400, FIG. 4). Alternatively, each of the dielectric resonators in the DRA array can be directly excited by the feed, which allows all the dielectric resonators to be classified as exciter resonators.

For example, FIGS. 5 and 6 are top and perspective views of a DRA array 500 according to example embodiments. The illustrated array 500 includes seven dielectric resonators 510 , 520 coupled to a substrate 530 . In one embodiment, dielectric resonator 510 , dielectric resonator 520 is physically coupled to the first side of substrate 530 to maintain a fixed spatial relationship between dielectric resonator 510 and dielectric resonator 520 . For example, the substrate 530 may be a rigid or flexible non-conductive material with good thermal conductivity. By way of example, and not limitation, substrate 530 may be formed of fiberglass (eg, woven fiberglass), polytetrafluoroethylene (PTFE), nylon, or other suitable materials. As will be discussed in more detail later in connection with FIG. 9, the substrate 530 material can be selected to provide sufficient electrical isolation from the underlying ground plane with which the substrate 530 can slidably engage.

A feed 550 configured to carry a radio frequency signal is placed within the center hole 512 of the center dielectric resonator 510 . So configured, center dielectric resonator 510 and feed 550 form a dielectric resonator antenna (DRA).

When a suitable radio frequency signal is carried by the feed 550, the signal will cause the center dielectric resonator 510 to resonate at its resonant frequency. This will then cause central dielectric resonator 510 to generate a primary electron field around the circumference of central dielectric resonator 510 (eg, electron field 440, Figure 4). In addition, the center dielectric resonator 510 can be generated from the center dielectric resonator 510 A secondary electron field (eg, electron field 442, Figure 4) extending orthogonally upward from the top surface of the .

According to one embodiment, center dielectric resonator 510 and adjacent dielectric resonator 520 are oriented in a coplanar manner, wherein dielectric resonator 510, the top surface and/or bottom surface of dielectric resonator 520 (or through the dielectric The cross-sections taken by resonator 510, dielectric resonator 520) are coplanar. Furthermore, center dielectric resonator 510 and adjacent dielectric resonator 520 are "closely capacitively coupled" to each other by positioning center dielectric resonator 510 and adjacent dielectric resonator 520 within a reasonably small distance 540 of each other . More specifically, the minimum distance 540 between the sidewalls of the dielectric resonator 510, the dielectric resonator 520 is chosen such that the dielectric resonator 510, the dielectric resonator 520 are closely spaced when a suitable excitation signal is provided to the feed 550. Capacitive coupling. According to one embodiment, the distance 540 between the center dielectric resonator 510 and the sidewalls of adjacent dielectric resonators 520 is less than one tenth of the wavelength of the resonant frequency of the center dielectric resonator 510 (or one tenth of λ) ). For example, for a resonant frequency of about 2.5 GHz, the distance 540 may be about 12.5 millimeters (mm) or less. According to another embodiment, the distance 540 is less than one fiftieth of λ. For example, for a resonant frequency of about 2.5 GHz, the distance 540 may be about 3.0 mm or less. In some embodiments, center dielectric resonator 510 and adjacent dielectric resonator 520 may be between about 1.0 mm and 2.0 mm apart. In yet another embodiment, the distance 540 may be zero (ie, as shown in FIG. 12, the center dielectric resonator 510 and the adjacent dielectric resonator 520 may be in contact).

As described above, when the center dielectric resonator 510 and the adjacent When the dielectric resonators 520 are in close proximity to each other, the circumferential or primary electron field (eg, electron field 440 , FIG. 4 ) generated by the center dielectric resonator 510 can directly impinge the adjacent dielectric resonators 520 . This in turn may cause adjacent dielectric resonators 520 to resonate at their respective resonant frequencies. Accordingly, the center dielectric resonator 510 may be classified as an "exciter resonator". In contrast, in the embodiment shown in Figure 5, no adjacent dielectric resonator 520 is directly excited by the feed. Therefore, they can be classified as "parasitic resonators".

Given a suitable excitation signal, the central dielectric resonator 510 and adjacent dielectric resonators 520 are capacitively coupled to each other, and each dielectric resonator 510, 520 resonates at its resonant frequency. Thus, the DRA array 500 of FIGS. 5 and 6 essentially includes a plurality of capacitively coupled resonators 510 , 520 . Each dielectric resonator 510, 520 is basically an antenna that can radiate efficiently in space, thus forming a "distributed antenna". As will become clearer from the description of FIG. 7, a decentralized antenna implemented by a DRA antenna (eg, DRA antenna 500) can efficiently couple to near-field loads (eg, a food load within a heating chamber) even when This is also true when the load is relatively small and/or the load is placed in various positions relative to the DRA antenna 500 .

Although the central dielectric resonator 510 may be excited by a feed 550 placed within the central aperture 512 of the dielectric resonator 510, the central dielectric resonator 510 may alternatively be aperture-coupled to a microstrip line 560 or other conductive structure, which Microstrip lines 560 or other conductive structures may alternatively be used to carry radio frequency signals for excitation of dielectric resonator 510 . Additionally or alternatively, the exciter dielectric resonator may be placed in locations other than the center hole by and/or multiple feed excitations that can be used to excite the dielectric resonator.

In the embodiment shown in FIGS. 5 and 6 , the DRA array 500 includes seven dielectric resonators 510 , 520 . In alternate embodiments, the DRA array may include any number of dielectric resonators in the range of 2 to 30 or more. Furthermore, all dielectric resonators 510, 520 are substantially the same size and shape. Assuming they are both formed of one or more materials with the same dielectric constant, then each of the dielectric resonators 510, 520 will resonate at substantially the same resonant frequency. In alternative embodiments, dielectric resonators may be selected that resonate at different resonant frequencies. This can be accomplished, for example, by using dielectric resonators of different sizes, dielectric resonators of different shapes, and/or dielectric resonators with different dielectric constants.

FIG. 7 is a circuit diagram 700 representing the electrical characteristics of a DRA having three adjacent dielectric resonators, according to one embodiment. More specifically, the first resonant circuit 710 represents an exciter dielectric resonator (eg, the center dielectric resonator 510, FIG. 5 ), and the second adjacent resonant circuit 720 and the third adjacent resonant circuit 730 represent locations positioned adjacent to Parasitic dielectric resonators of the first (exciter) resonator 710 (eg, two dielectric resonators 520, Figure 5). According to one embodiment, the feed is placed near the exciter dielectric resonator (or first resonant circuit 710 ), and by capacitive coupling, the exciter dielectric resonator (or first resonant circuit 710 ) is coupled to the parasitic dielectric resonance (or the second resonant circuit 720 and the third resonant circuit 730).

As described above, the parasitic dielectric resonator is placed close enough to the exciter dielectric resonator to ensure that the resonators are tightly capacitively coupled, as represented by capacitor 740 . Basically, the resonant circuits 710, 720, 730 The capacitive coupling between (ie, the value of capacitor 740 ) is inversely proportional to the distance between the dielectric resonators represented by resonant circuits 710 , 720 , 730 . Different spacings between dielectric resonators cause different strengths of capacitive coupling and different frequency responses. More specifically, changes in the frequency response can significantly affect the bandwidth of circuit 700 . In some embodiments, the dielectric resonators may be sized, shaped, and positioned relative to each other to form a relatively broadband circuit 700 . In other words, individual dielectric resonators can be placed (or capacitively coupled together) to give a composite composite broadband response.

In the electronic representation of Figure 7, each resonant circuit 710, 720, 730 includes a parallel inductor and capacitor (which together form a resonator) and a resistor (Rr) representing the radiation resistance. More specifically, because the DRA array represented by circuit 700 is used to radiate energy into the heating chamber, the radiation resistance represents the energy loss into the chamber due to the radiation of energy away from the DRA array. Each of the resonators in the resonant circuits 710, 720, 730 may radiate at the same frequency (eg, when the dielectric resonators are the same), or the resonators in the resonant circuits 710, 720, 730 may be at different frequencies Resonance (eg, when the dielectric resonators are of different sizes, shapes and/or dielectric constants).

Figure 8 is a graph depicting the gain bandwidth of a DRA array (eg, DRA array 500, Figure 5), according to one embodiment. More specifically, the graph depicts the gain bandwidth of an embodiment of a DRA antenna with an unloaded center frequency of about 2.45 GHz. A DRA with a single dielectric resonator can have a fairly narrowband response (eg, between about 2.4 GHz and 2.5 GHz). However, embodiments of DRA arrays discussed above (and later) include to One less DRA and one or more adjacent dielectric resonators that technically increase the aperture of the antenna, which results in a significantly wider frequency band response (eg, at the -10dB point, between about 2.3GHz and 2.6GHz about 200MHz bandwidth).

Due to the relatively broad frequency response and as will be discussed in more detail below, embodiments of the DRA array may be extremely insensitive to near-field loading compared to conventional monopoles, patch antennas, or other types of narrowband antennas. This makes DRA array embodiments particularly suitable for microwave heating applications where the heating chamber is in close proximity to the radiation element (in this case, the DRA array). As is known in antenna theory, a large amount of near-field loading can cause a relatively narrowband antenna to become detuned to the extent that the energy produced by the antenna is shifted away from the desired unloaded frequency band. If this were the case in a microwave heating application, the antenna would not be able to transmit energy into the heating chamber. However, the broad frequency response of the various embodiments of the DRA array structure ensures that the DRA array structure can transmit substantial amounts of energy into the heating chamber and load in the frequency band of interest (in the frequency band centered around 2.45 GHz), even when the load The same is true for near-field loads (eg, food loads placed in a heating chamber adjacent to the DRA array structure). In other words, even if the near-field load causes the DRA array structure to respond in frequency, embodiments of the DRA array structure are sufficiently broadband such that the response does not move outside the relatively broadband, thus allowing efficient energy transfer to the near-field load middle. The DRA array develops a broadband frequency response that is extremely insensitive to near-field loads and loads placed within the heating chamber. Furthermore, the broad frequency response of DRA array embodiments ensures that energy can be efficiently delivered to food loads with a wide variety of dielectric constants. Due to the wide bandwidth of various embodiments of the DRA array, emission to adjacent heating chambers The efficiency can be as high as 95% or higher.

9 is a cross-sectional side view of the portable microwave heating apparatus 100 of FIGS. 1 and 2, according to an example embodiment. Microwave heating apparatus 900 includes a housing 910, a heating chamber 920, a system controller (eg, system controller 310, not shown in FIG. 9), a user interface (eg, user interface 330, not shown in FIG. 9) , a power supply system (eg, power supply system 340 , not shown in FIG. 9 ), a microwave power generation module 950 (eg, module 350 , FIG. 3 ), one or more DRA arrays 960 , 962 (eg, DRA array 360 ) , 500, Figures 3, 5) and other components discussed in more detail below. According to one embodiment and as will be discussed in detail below, the first DRA array 960 may be placed within the base portion 912 of the housing 910 . In another embodiment, the device 900 may include one or more additional DRA arrays, such as a second DRA array 962 located within the cover 916 .

In one embodiment, the housing 910 includes a base portion 912, a chamber portion 914, and a lid 916 (which is in a closed state in FIG. 9). In one embodiment, the heating chamber 920 is located within the chamber portion 914 of the housing 910 and extends upwardly into the interior of the lid 916 . Heating chamber 920 is defined by inner side walls 922 , chamber bottom surface 924 and chamber top surface 926 . FIG. 9 shows a load 940 (eg, a food load or other load) within the chamber 920 . As previously described, as shown in Figure 9, by closing lid 916, heating chamber 920 is a closed air chamber that essentially acts as a waveguide with closed ends. In the illustrated embodiment, the heating chamber 920 has a generally circular cross-section, which results in the heating chamber 920 being a cylindrical waveguide. In other embodiments, the chamber may have a rectangular cross-section, an oval cross-section or have other shaped sections.

In one embodiment, the chamber walls may be formed from a material with good thermal conductivity. For example, the chamber walls may be formed from copper, aluminum, steel, or other suitable materials. In some embodiments, the inner sidewall 922 of the chamber 920 may be coated with a material that affects the frequency of the chamber 920 . For example, inner sidewall 922 may be coated with PTFE, nylon, or other suitable material that may reduce or affect the frequency of chamber 920.

According to one embodiment, the base portion 912 of the housing 910 includes a first DRA array 960 and at least one electronic substrate 970 . For example, the electronic substrate 970 may comprise a microwave or radio frequency laminate, a PTFE substrate, a printed circuit board (PCB) material substrate (eg, FR-4), an alumina substrate, ceramic tile, or another type of substrate. According to one embodiment, electronic substrate 970 includes a conductive ground plane 972 (eg, the upper surface in FIG. 9 ) on or near a first surface of electronic substrate 970 and one or more other conductive layers, the one or more Some of the other conductive layers may be patterned to provide electrical interconnection between various components mounted to the electronic substrate 970 . For example, in one embodiment, components corresponding to the system controller, portions of the user interface, power supply, and microwave power generation module 950 may be mounted to the second surface of the electronic substrate 970 (eg, in FIG. 9 ). lower surface), and those components can be electrically coupled to each other through a patterned conductive layer on or below the second surface.

In one embodiment, the first DRA array 960 may be configured similarly to the DRA array 500 (FIG. 5), although it may also be configured differently. When the first DRA array 960 is configured like the DRA array 500 (FIG. 5), the first A DRA array 960 may include one or more exciter resonators 964 and adjacent parasitic resonators 966, wherein the parasitic resonators 966 are tightly capacitively coupled to the exciter resonators 964 as previously described. As described in connection with FIG. 5 , exciter resonator 964 and parasitic resonator 966 may be coupled to a DRA array substrate 980 (eg, substrate 530 , FIG. 5 ) slidably with a first surface of electronic substrate 970 (eg, with ground plane 972). According to one embodiment, a non-conductive cover 982 is disposed between the first DRA array 960 and the chamber 920 . The cover 982 serves to protect the DRA array 960 from moisture and other contaminants (eg, food splashes) and defines the bottom surface 924 of the chamber 920 .

In the illustrated embodiment, a feed 968 configured to carry a radio frequency signal is placed within the central hole of the exciter resonator 964 . According to one embodiment, the diameter of the feed 968 is smaller than the diameter of the central hole so that the feed 968 does not compress the inner sidewall of the central hole and potentially cause the exciter resonator 964 to crack when it undergoes thermal expansion. So configured, the driver resonator 964 and feed 968 form a DRA, and the DRA and parasitic resonator 966 form a first DRA array 960 .

As previously described, microwave power generation module 950 includes a tuning circuit (eg, tuning circuit 354, FIG. 3), a bias circuit (eg, bias circuit 356, FIG. 3), and an oscillator subsystem (eg, oscillator sub-system system 352, Figure 3). In one embodiment, the oscillator subsystem includes one or more power transistors 952 . To assist in providing an oscillating radio frequency signal to the feed 968 , the output (eg, drain terminal) of the power transistor 952 (or the output of the power amplifier) is electrically coupled to the feed through a conductive transmission line 954 968 , the conductive transmission lines 954 are on or below the second surface of the electronic substrate 970 . Feeds 968 extend through holes in electronics substrate 970 , through holes in DRA array substrate 980 , and into the center hole in driver resonator 964 .

In response to user input provided by a user interface (eg, by control panel 130, FIG. 1), a system controller (eg, controller 310, FIG. 3) causes microwave power generation module 950 to generate one or more excitation signals Provided to DRA arrays 960, 962. In response, each DRA array 960 , 962 radiates electromagnetic energy (indicated by shading region 990 ) into the heating chamber 920 . The microwave energy increases the thermal energy of the load 940 and can heat the load.

As described above, when the exciter resonator 964 is properly excited by the radio frequency signal carried on the feed 968, the exciter resonator 964 resonates at the resonant frequency and generates a circumferential electron field (eg, electron field 440, FIG. 4) and the vertical electron field (eg, electron field 442, Figure 4). According to one embodiment, the circumferential electron fields impinge the parasitic resonators 966 directly, causing them to resonate at their resonant frequency. This allows parasitic resonator 966 to also generate circumferential and vertical electron fields. Basically, each resonator 964, 966 of the DRA array 960 has a radiation pattern. Given the nature of the electron field and the presence of ground plane 972, the accumulated radiation is directed towards and into chamber 920 in a comparable directional beam. In other words, the DRA array 960 acts as an antenna array that directs a relatively narrow fixed beam of electromagnetic energy into the chamber 920 .

As previously mentioned, the chamber 920 essentially acts as a seal with A closed-ended electromagnetic waveguide in which electromagnetic waves within the chamber 920 generally travel in a direction from the DRA array 960 to the top surface 926 of the chamber 920 . More specifically, electromagnetic waves may propagate through chamber 920 in one or more propagation modes including one or more transverse electric (TE) modes, transverse magnetic (TM) modes, and/or Mixed transverse electric and transverse magnetic (TEM) modes. However, electromagnetic waves will propagate in the chamber 920 only when the frequency of the electromagnetic energy generated by the DRA arrays 960, 962 exceeds a lower threshold or the minimum frequency of the chamber 920 (often referred to as the cutoff frequency).

The cutoff frequency of the chamber 920 is defined by the size (eg, defined by height and diameter) and shape (eg, cylindrical, rectangular, elliptical, etc.) of the chamber 920 . According to one embodiment, and regardless of the loading due to the presence of the DRA arrays 960, 962 or the loading 940 present within the chamber 920, the size and shape of the chamber 920 presents the chamber 920 below the cut-off point. In other words, the DRA arrays 960, 962 and loads are not present in the frequency band required for operation of microwave heating (eg, between 2.3 GHz and 2.6 GHz, and referred to hereinafter as the "Microwave Heating Band") At 940, the chamber 920 is configured such that no mode can propagate in the chamber 920 for electromagnetic energy in the microwave heating band regardless of how it is excited. For example, when unloaded, the chamber 920 may have a size and shape that may not support any propagation modes when excited by electromagnetic energy below 3.0 GHz.

However, in microwave heating device 900 and due in part to the higher permittivity of dielectric resonators 964, 966, DRA array 960, 962 is used to load the chamber 920 in a manner that enables one or more modes to propagate within the chamber 920 in the microwave heating band. In other words, the loading provided by the DRA arrays 960, 962 brings the chamber 920 to a resonant frequency within the microwave heating band (ie, the chamber 920 is not below the cutoff point when loaded by the DRA arrays 960, 962) . In other words, in one embodiment, by including the DRA arrays 960, 962 within the chamber 920, the cutoff frequency of the additional chambers 920 below the cutoff point is lowered into the microwave heating band. Thus, when the chamber is excited by electromagnetic energy (from the DRA arrays 960, 962) in the microwave heating band, one or more modes may propagate within the chamber 920, even though the unloaded chamber 920 may be too small to support The same goes for the spread of those patterns.

In one embodiment, depending on the shape, size and cutoff frequency of the loading chamber 920, the optimal mode of propagation will be found almost naturally. Ideally, chamber 920 is designed to support mixed and/or complex modes, which may be advantageous in situations where uniform heating of inserted load 940 may be enhanced when electromagnetic chaos is created within chamber 920 . In other words, uniform heating across load 940 may be more easily achieved when multiple modes and/or higher order modes are propagated in chamber 920 . Since the feed 968 can cause the electron field to be generated in three orthogonal directions (eg, X, Y, and Z), the main mode in the chamber 920 can be excited automatically.

In some embodiments, substantially the DRA arrays 960, 962 are configured to efficiently couple energy into the chamber 920 even though the chamber 920 may be below the cutoff point. As noted above, although embodiments of microwave heating apparatus 900 may include an unloaded chamber below the cutoff point 920, but in other embodiments, the unloaded chamber 920 may be sized and shaped to present the chamber 920 above the cut-off point (or, when excited by electromagnetic energy in the microwave heating band, to support one or Multiple propagation modes, even in the absence of loading through the DRA arrays 960, 962).

During operation, a load 940 (eg, a food load) in the chamber 920 provides additional load in addition to the load provided by the DRA arrays 960, 962. More specifically, when placed as shown in FIG. 9 , the load 940 is in the near field of the DRA array 960 . Using conventional antennas (eg, monopoles or patch antennas), such near-field loads can detune the antenna to the extent that the antenna may not couple energy into the chamber or load. However, as discussed in detail beforehand, the broadband nature of the DRA arrays 960, 962 makes them extremely insensitive to near-field loading. Thus, the DRA arrays 960 , 962 can efficiently couple energy into the chamber 920 and the load 940 even in the presence of the near-field load 940 .

9, the DRA array 960 is separated from the chamber 920 by a non-conductive cover 982 disposed between the DRA array 960 and the chamber 920, wherein the cover 982 is used to protect the DRA array 960 from moisture and effects of other pollutants. In alternative embodiments, such as the embodiment shown in FIG. 10, a conformal coating 1082 may be used to protect the DRA array 1060. For example, FIG. 10 is a cross-sectional side view of a portion of a portable microwave heating apparatus 1000 according to another example embodiment. More specifically, the portion of the microwave heating device 1000 corresponds to the base portion 1012 of the device 1000 .

Base portion 1012 and base portion 912 of device 1000 (FIG. 9) Similarly, in the base portion 1012 the assembly includes a DRA array 1060 and a substrate 1070. The DRA array 1060 may include one or more exciter resonators 1064 and adjacent parasitic resonators 1066, wherein the parasitic resonators 1066 are tightly capacitively coupled to the exciter resonators 1064 as previously described. As described in connection with FIG. 5 , the exciter resonator 1064 and the parasitic resonator 1066 may be coupled to a DRA array substrate 1080 (eg, substrate 530 , FIG. 5 ) that slides with the first surface of the electronic substrate 1070 (eg, with ground plane 1072).

Substrate 1070 includes a conductive ground plane 1072 on or near a first surface of substrate 1070 (eg, the upper surface in FIG. 10 ) and one or more other conductive layers, some of which may be are patterned to provide electrical interconnections between various components mounted to the substrate 1070 . For example, in one embodiment, components corresponding to the system controller, the portion of the user interface, the power supply, and the microwave power generation module 1050 may be mounted to the second surface of the substrate 1070 (eg, the lower portion in FIG. 10 ) surface), and those components can be electrically coupled to each other through a patterned conductive layer that is on or below the second surface.

In contrast to the microwave heating apparatus 900 of FIG. 9, a conformal coating 1082 is used to protect the DRA array 1060 from moisture and other contaminants. For example, the conformal coating 1082 may include a non-conductive encapsulation material, such as thermoset plastic, ABS plastic, epoxy, PTFE, or other suitable materials. According to one embodiment, conformal coating 1082 may define a bottom surface of a chamber (not shown) placed over base portion 1012 1024.

As previously mentioned, alternative embodiments of microwave heating devices may include dielectric resonators with apertures coupled to a radio frequency signal source rather than through an exciter resonator (eg, resonator 964) placed in the DRA array ) within the feed (eg, feed 968, Figure 9) coupling. For example, FIG. 11 is a cross-sectional side view of a portion of a portable microwave heating device 1100 that includes an aperture-coupled DRA array 1160 according to another example embodiment. More specifically, the portion of the microwave heating device 1100 corresponds to the base portion 1112 of the device 1100 .

The base portion 1112 of the device 1100 is similar to the base portion 912 ( FIG. 9 ) in which the assembly includes the DRA array 1160 and the substrate 1170 . The DRA array 1160 may include one or more exciter resonators 1164 and adjacent parasitic resonators 1166, wherein the parasitic resonators 1166 are tightly capacitively coupled to the exciter resonators 1164 as previously described. As described in connection with FIG. 5 , the exciter resonator 1164 and the parasitic resonator 1166 may be coupled to a DRA array substrate 1180 (eg, substrate 530 , FIG. 5 ) that slides with the first surface of the electronic substrate 1170 (eg, with ground plane 1172).

Substrate 1170 includes a conductive ground plane 1172 on or near a first surface of substrate 1170 (eg, the upper surface in FIG. 11 ) and one or more other conductive layers, some of which may be are patterned to provide electrical interconnections between various components mounted to the substrate 1170 . For example, in one embodiment, components corresponding to the system controller, portions of the user interface, power supplies, and microwave power may be combined The rate generation modules 1150 are mounted to the second surface of the substrate 1170 (eg, the lower surface in FIG. 11 ), and those components can be electrically coupled to each other through a patterned conductive layer on the second surface or below the second surface.

According to one embodiment, the ground plane 1172 includes an opening or aperture 1174 below the exciter resonator 1164 . Additionally, microstrip lines 1176 or other conductive structures on or below the surface of the electronic substrate 1170 (eg, the lower surface in FIG. 11 ) or below the surface of the electronic substrate 1170 (eg, the lower surface in FIG. 11 ) are underlying ground Aperture 1174 in plane 1172, and also underlying exciter resonator 1164.

In one embodiment, the microstrip line 1176 is electrically coupled to the output of an oscillator subsystem (eg, oscillator subsystem 352, FIG. 3), and more specifically to the output of the oscillator subsystem's power transistor 1152 output (eg, drain terminal). When a suitable radio frequency signal is provided to the microstrip line 1176, the microstrip line 1176 generates electromagnetic energy that is coupled to the exciter resonator 1164 through the electronic substrate 1170 (and more specifically, through the aperture 1174 in the ground plane 1172). . When the coupled RF energy is sufficient to cause the exciter resonator 1164 to resonate and generate its own electron fields, those electron fields can directly impinge on the parasitic resonator 1166 . The parasitic resonator 1166 can then resonate and generate additional electron fields. Likewise, the electron fields generated by the exciter resonator 1164 and the parasitic resonator 1166 may extend into and couple with a cavity (not shown) placed above the base portion 1112 .

The different configurations will now be described in conjunction with FIGS. 12 to 17 Various embodiments of DRA arrays. For example, FIG. 12 is a top view of a DRA array 1200 suitable for use in a microwave heating apparatus according to another example embodiment. Similar to the DRA array 500 of FIG. 5 , the DRA array 1200 includes seven dielectric resonators 1210 , 1220 coupled to a substrate 1230 including a central exciter resonator 1210 and adjacent parasitic resonators 1220 . Substrate 1230 may be generally similar to substrate 530 (FIG. 5), which includes variations of substrate 530 discussed above. In one embodiment, the feed 1250 configured to carry the radio frequency signal is placed within the center hole of the center or exciter dielectric resonator 1210 . So configured, exciter resonator 1210 and feed 1250 form a DRA. In alternative embodiments, the exciter resonator 1210 may alternatively be pore-coupled to a microstrip line 1260 or other conductive structure, which may alternatively be used to carry radio frequency signals for exciting the exciter resonance device 1210. Additionally or alternatively, the exciter resonator may be excited by a feed placed in a location other than the central hole and/or by multiple feeds that may be used to excite the dielectric resonator.

As with DRA array 500, when an appropriate radio frequency signal is carried by feed 1250 or microstrip line 1260, the signal will cause exciter resonator 1210 to resonate at its resonant frequency. This in turn will cause exciter resonator 1210 to generate a primary electron field (eg, electron field 440, Figure 4) around the circumference of exciter resonator 1210. Additionally, the exciter resonator 1210 may generate a secondary electron field (eg, electron field 442, FIG. 4 ) that extends orthogonally upward from the top surface of the exciter resonator 1210 .

In contrast to the DRA 500, the exciter resonator 1210 and the adjacent parasitic dielectric resonator 1220 are formed by placing the exciter resonator 1210 and the parasitic dielectric resonator 1220. The resonators 1220 are capacitively coupled more closely to each other so that they actually touch each other. More specifically, the distance between the sidewalls of the dielectric resonators 1210 , 1220 is zero, so that the dielectric resonators 1210 , 1220 are capacitively coupled extremely tightly when an appropriate excitation signal is provided to the feed 1250 or 1260 .

As described above, when the exciter resonator 1210 and the parasitic resonator 1220 are in contact, the circumferential or primary electron field (eg, electron field 440, FIG. 4) generated by the exciter resonator 1210 can directly impinge adjacent parasitic resonances device 1220. This in turn may cause the parasitic resonators 1220 to resonate at their respective resonant frequencies.

13 is a top view of a DRA array 1300 suitable for use in a microwave heating apparatus according to another example embodiment. DRA array 1300 includes seven dielectric resonators 1310 to 1313 coupled to substrate 1330 , dielectric resonator 1320 including a plurality of exciter resonators 1310 to 1313 and adjacent parasitic resonator 1320 . Substrate 1330 may be substantially similar to substrate 530 (FIG. 5), which includes variations of substrate 530 discussed above. In the illustrated embodiment, a plurality of feeds 1350 configured to carry one or more radio frequency signals are placed within the central bores of the plurality of exciter resonators 1310-1313. So configured, each of the exciter resonators 1310-1313 and its associated feed 1350 form a DRA. Thus, DRA array 1300 includes multiple DRAs in contrast to the embodiment of FIG. 5 in which DRA array 500 includes only a single DRA. In alternate embodiments, one or more of the exciter resonators 1310-1313 may alternatively be pore-coupled to a microstrip line 1360 or some other conductive structure, the microstrip line 1360 or some other conductive structure. Its conductive structure may alternatively be used to carry radio frequency signals for excitation of the exciter resonators 1310-1313. In yet another alternative embodiment, as indicated for the central exciter resonator 1310, multiple feeds 1350, 1352 may be placed at different locations within a given dielectric resonator 1310-1313. In some embodiments, the different feeds may be coupled (or configured to excite) up to all the dielectric resonators in the array (eg, all the dielectric resonators may be exciter resonators).

As with the DRA array 500, when an appropriate radio frequency signal is carried by the feeds 1350, 1352 or the microstrip line 1360, the signal will cause the corresponding exciter resonators 1310 to 1313 to resonate at their resonant frequencies. This in turn will cause exciter resonators 1310-1313 to generate a primary electron field (eg, electron field 440, Figure 4) around the circumference of exciter resonators 1310-1313. Further exciter resonators 1310-1313 may generate secondary electron fields (eg, electron fields 442, FIG. 4) extending orthogonally upward from the top surfaces of exciter resonators 1310-1313. In some cases, an exciter resonator 1310-1313 may be in close proximity (ie, tightly capacitively coupled without intervening structures) to another exciter resonator 1310-1313. In such cases, adjacent exciter resonators 1310-1313 may act as both exciter resonators and parasitic resonators. For example, considering resonators 1310 and 1311 in close proximity to each other, when exciter resonator 1310 is active and generates a circumferential electron field (eg, electron field 440, FIG. 4), the electron field may directly impinge on the exciter Resonator 1311. During these times, the exciter resonator 1311 may act as a parasitic resonator. If the exciter resonator 1311 also receives input from the feed 1350 or the microstrip line 1360 associated with the exciter resonator 1311 excitation, then simultaneously the exciter resonator 1311 can act as both an exciter resonator and a parasitic resonator.

According to one embodiment, all feeds 1350, 1352 and/or microstrip lines 1360 may receive the same radio frequency signal. In various alternative embodiments, the feeds 1350, 1352 and/or the microstrip line 1360 may receive different radio frequency signals (eg, at different frequencies and/or power levels) and/or may provide the radio frequency signals in stages to feeds 1350, 1352 and/or microstrip line 1360. For example, during a first duration, excitation from their associated feeds 1350 and/or feeds 1352 and/or microstrip lines 1360 may be provided to a first subset of exciter resonators 1310, while the exciter A second and different subset of resonators 1310 may receive no excitation or a different excitation from their associated feeds 1350 and/or feeds 1352 and/or microstrip lines 1360 . During the second duration, the excitation provided to the first subset of exciter resonators 1310 may be removed or changed, and the excitation provided to the second subset of exciter resonators 1310 may remain the same or may also be removed Or change the excitation provided to the second subset of exciter resonators 1310. In this manner, the accumulated electron field produced by the DRA array 1300 may change direction, intensity, frequency, or other parameters over time. In other words, by providing multiple feeds 1350, 1352 and/or microstrip lines 1360 and exciting them sequentially or in various combinations, continuously or incrementally steerable beams can be formed. More specifically, by activating multiple feeds 1350, 1352 and/or microstrip lines 1360 individually or in combination, the beam of microwave energy can be steered in azimuth and/or elevation.

Figure 14 is suitable for use in microwaves according to yet another example embodiment Top view of DRA array 1400 in a heating device. While each of the DRA arrays previously described has been indicated for use in a microwave heating system that includes a heating chamber having a circular cross-section (eg, chamber 920, FIG. 9 ), the DRA array 1400 of FIG. 14 may be specifically Said is well suited for use in microwave heating devices comprising heating chambers with rectangular cross-sections. In other words, the DRA array 1400 may be well suited for use in systems that include heating chambers that essentially act as rectangular waveguides with closed ends.

In the illustrated embodiment, the DRA array 1400 includes eleven dielectric resonators 1410 - 1412 , 1420 coupled to a rectangular substrate 1430 , including a plurality of exciter resonators 1410 - 1412 and an adjacent parasitic resonator 1420 . Except for the shape, substrate 1430 may be generally similar to substrate 530 (FIG. 5), which includes variations of substrate 530 discussed above. In the illustrated embodiment, a plurality of feeds 1450 configured to carry one or more radio frequency signals are placed within the central bores of the plurality of exciter resonators 1410-1412. So configured, each of the exciter resonators 1410-1412 and its associated feed 1450 form a DRA. Thus, DRA array 1400 includes multiple DRAs. In alternative embodiments, one or more of the exciter resonators 1410-1412 may alternatively be pore-coupled to a microstrip line 1460 or some other conductive structure, which may alternatively be used for A radio frequency signal is carried for excitation of the exciter resonators 1410-1412.

As with the DRA array 500, when an appropriate radio frequency signal is carried by the feed 1450 or the microstrip line 1460, the signal will cause the corresponding exciter resonators 1410 to 1412 to resonate at their resonant frequencies. This in turn will make the The exciter resonators 1410-1412 generate a primary electron field (eg, electron field 440, FIG. 4) around the circumference of the exciter resonators 1410-1412. In addition, exciter resonators 1410-1412 may generate secondary electron fields (eg, electron fields 442, FIG. 4) that extend orthogonally upward from the top surfaces of exciter resonators 1410-1412.

As with the embodiment of FIG. 13 and according to one embodiment, all feeds 1450 and/or microstrip lines 1460 may receive the same radio frequency signal. In various alternative embodiments, feed 1450 and/or microstrip line 1460 may receive different radio frequency signals (eg, at different frequencies and/or power levels) and/or may provide radio frequency signals to the feed in stages 1450 and/or microstrip line 1460.

15 is a top view of a DRA array 1500 suitable for use in a microwave heating apparatus according to yet another example embodiment. The DRA array 1500 is similar to the DRA array 1300 in FIG. 13, except that the DRA array 1500 includes additional rows of circumferentially placed dielectric resonators instead of only a single row of circumferentially placed dielectric resonators (as in FIG. 13 in the DRA array 1300). More specifically, DRA array 1500 includes nineteen dielectric resonators 1510, 1512, 1520, 1522 coupled to substrate 1530, including a plurality of exciter resonators 1510, 1512 and adjacent parasitic resonators 1520, 1522. More specifically, the DRA array 1500 includes a centrally positioned exciter resonator 1510, a first circumferential row of parasitic resonators 1520 next to the central exciter resonator 1510, and a second circumferential row of alternating exciter resonators 1512 and Parasitic resonator 1522.

In a DRA array 1300 like FIG. 13, configured to carry Multiple feeds 1550 with one or more radio frequency signals are placed within the central holes of the multiple exciter resonators 1510, 1512. So configured, each of the exciter resonators 1510, 1512 and its associated feed 1550 form a DRA. In alternative embodiments, one or more of the exciter resonators 1510, 1512 may alternatively be pore-coupled to a microstrip line 1560 or some other conductive structure, which may alternatively be used for A radio frequency signal is carried for excitation of the exciter resonators 1510, 1512.

As with the DRA array 500, when an appropriate radio frequency signal is carried by the feed 1550 or the microstrip line 1560, the signal will cause the corresponding exciter resonator 1510, 1512 to resonate at its resonant frequency. This in turn will cause the exciter resonators 1510, 1512 to generate a primary electron field (eg, electron field 440, Figure 4) around the circumference of the exciter resonators 1510, 1512. Additionally, the exciter resonators 1510, 1512 may generate secondary electron fields (eg, electron fields 442, FIG. 4) that extend orthogonally upward from the top surfaces of the exciter resonators 1510, 1512.

According to one embodiment, all feeds 1550 and/or microstrip lines 1560 may receive the same radio frequency signal. In various alternative embodiments, feed 1550 and/or microstrip line 1560 may receive different radio frequency signals (eg, at different frequencies and/or power levels), and/or may provide radio frequency signals to Feed 1550 and/or microstrip line 1560.

In some alternative embodiments, the DRA array may include dielectric resonators that resonate at different frequencies. As discussed previously, for example, This can be accomplished by using dielectric resonators of different sizes, dielectric resonators of different shapes, and/or dielectric resonators with different dielectric constants. 16 is a perspective view of a DRA array 1600 suitable for use in a microwave heating apparatus, the DRA array 1600 including dielectric resonators 1610, 1620, 1630 of different sizes, according to another example embodiment. Similar to DRA array 500 of FIG. 5 , DRA array 1600 includes seven dielectric resonators 1610 , 1620 , 1630 coupled to substrate 1640 , including at least one exciter resonator (eg, any of resonators 1610 , 1620 , 1630 ) one or more) and adjacent parasitic resonators (eg, any other one or more of resonators 1610, 1620, 1630). Substrate 1640 may be generally similar to substrate 530 (FIG. 5), which includes variations of substrate 530 discussed above. In one embodiment, a feed (not shown) configured to carry a radio frequency signal is placed within the central hole of each exciter dielectric resonator. So configured, the exciter resonator and feed form a DRA. In alternative embodiments, each exciter resonator may alternatively be pore-coupled to a microstrip line or other conductive structure, which may alternatively be used to carry radio frequency signals for exciting the exciter resonators . Additionally or alternatively, the exciter resonator may be excited by a feed placed in a location other than the central hole and/or by multiple feeds that may be used to excite the dielectric resonator.

As with array 500, when a suitable radio frequency signal is carried by the feed or microstrip line, the signal will cause the exciter resonator to resonate at its resonant frequency. This, in turn, will cause the exciter resonator to generate a primary electron field around the circumference of the exciter resonator (eg, electron field 440, Figure 4). Additionally, the exciter resonator may generate a positive upward direction from the top surface of the exciter resonator. A secondary electron field that extends across the ground (eg, electron field 442, Figure 4).

In contrast to the DRA 500, the dielectric resonators 1610, 1620, 1630 are of different sizes. Assuming that the dielectric resonators 1610, 1620, 1630 are formed of materials having the same dielectric constant, the magnitude difference causes the dielectric resonators 1610, 1620, 1630 to resonate at different resonant frequencies. For example, the largest dielectric resonator 1610 can resonate at a first resonant frequency, an intermediate-sized dielectric resonator 1620 can resonate at a second higher resonant frequency, and the smallest dielectric resonator 1630 can resonate at a third or even Resonates at higher resonant frequencies. Due to differences in resonant frequencies, the accumulated electron fields originating from the DRA array 1600 may be non-orthogonal to the upper surfaces (eg, upper surface 1640 ) of the dielectric resonators 1610 , 1620 , 1630 .

Although the electronic field steering is achieved in the DRA array 1600 of FIG. 16 by incorporating different sized dielectric resonators 1610, 1620, 1630 into the array 1600 (thus the resonators have different resonant frequencies), similar beam steering effects Can be achieved in other ways. For example, electron field manipulation may alternatively be achieved by incorporating dielectric resonators with different dielectric constants into the array, incorporating differently shaped dielectric resonators into the array, or changing the proximity The spacing between groups of dielectric resonators and thus changes the strength of the capacitive coupling. By incorporating dielectric resonators with various resonant frequencies into a DRA array, systems can be designed in which the accumulated electron field is guide.

In some alternative embodiments, the DRA array may be included in dielectric resonators having different physical configurations and thus resonate at different frequencies and/or dielectric resonators with different electron field distributions. For example, Figure 17 is a perspective view of a DRA array 1700 suitable for use in a microwave heating apparatus including dielectric resonators 1710, 1720, 1730 in different physical configurations, according to another example embodiment. DRA array 1700 includes eleven dielectric resonators 1710, 1720, 1730 coupled to substrate 1740, including at least one exciter resonator (eg, any one or more of resonators 1710, 1720, 1730) and adjacent parasitic A resonator (eg, any other one or more of resonators 1710, 1720, 1730). Substrate 1740 may be generally similar to substrate 530 (FIG. 5), which includes variations of substrate 530 discussed above. In one embodiment, a feed (not shown) configured to carry a radio frequency signal is placed within the central hole of each exciter dielectric resonator. So configured, the exciter resonator and feed form a DRA. In alternative embodiments, each exciter resonator may alternatively be pore-coupled to a microstrip line or other conductive structure, which may alternatively be used to carry radio frequency signals for exciting the exciter resonators . Additionally or alternatively, the exciter resonator may be excited by a feed placed in a location other than the central hole and/or by multiple feeds that may be used to excite the dielectric resonator.

As with array 500, when a suitable radio frequency signal is carried by the feed or microstrip line, the signal will cause the exciter resonator to resonate at its resonant frequency. This in turn will cause the exciter resonator to generate one or more electron fields that radiate outward from the resonator.

In contrast to the DRA 500, the dielectric resonators 1710, 1720, 1730 have different physical configurations. Specifically, in the implementation shown For example, the first dielectric resonator 1710 has a generally cylindrical shape with a center hole, the second dielectric resonator 1720 has a generally cylindrical shape without a center hole, and the third dielectric resonator 1730 Has a dome shape with a central hole. Given that the dielectric resonators 1710, 1720, 1730 are formed of materials with the same dielectric constant, the physical configuration differences cause the dielectric resonators 1710, 1720, 1730 to resonate at different resonant frequencies and/or generate electron fields with different distributions.

The embodiment of FIG. 17 shows that a variety of different configurations of dielectric resonators can be used in various embodiments of DRA arrays. To illustrate this further, Figures 18-23 are perspective views of dielectric resonators 1800, 1900, 2000, 2100, 2200, 2300 having various physical configurations and which may be used in DRA arrays. More specifically, dielectric resonator 1800 (FIG. 18) has a cylindrical shape without a center hole, dielectric resonator 1900 (FIG. 19) has a flat disc shape with a center hole, and dielectric resonator 2000 (FIG. 19) has a flat disk shape with a center hole. 20) has a conical shape with a center hole, the dielectric resonator 2100 (FIG. 21) has a parallelepiped shape with a center hole, the dielectric resonator 2200 (FIG. 22) has a spherical shape with a center hole, and the dielectric The resonator 2300 (FIG. 23) has a dome shape without a central hole. Any of a wide variety of different configurations of dielectric resonators with or without a central hole or with other openings may alternatively be used in various embodiments.

As indicated previously, other alternative embodiments of microwave heating apparatus may include more than one DRA array. For example, in FIG. 9, an additional DRA array 962 is depicted in the lid 916 of the microwave heating apparatus 900. In this embodiment, the two included DRA arrays 960, 962 are The beams of electromagnetic energy are configured to be directed along the same axis, specifically the axis extending perpendicular to the bottom surface 924 and the top surface 926 of the heating chamber 920 . In alternative embodiments, the microwave heating apparatus may include multiple DRA arrays that direct beams of electromagnetic energy in multiple directions that are not collinear. For example, Figure 19 is a cross-sectional side view of a microwave heating apparatus 1900 including a first DRA array 2460 and a second DRA that direct beams of electromagnetic energy in orthogonal directions, according to another example embodiment Array 2462.

Similar to microwave heating apparatus 900 of FIG. 9, microwave heating apparatus 2400 includes a housing 2410, a heating chamber 2420, a system controller (eg, system controller 310, not shown in FIG. 24), a user interface (eg, a user interface) interface 330, not shown in FIG. 24), and a power system (eg, power system 340, not shown in FIG. 24). Additionally, in one embodiment, the housing 2410 includes a base portion 2412, a chamber portion 2414, and a lid 2416 (which is in a closed state in Figure 24). In contrast to microwave heating apparatus 900 of Figure 9, microwave heating apparatus 2400 includes two microwave power generating modules 2450, 2452 (eg, two instances of module 350, Figure 3), and arranged orthogonally with respect to each other Two DRA arrays 2460, 2462 (eg, two instances of DRA arrays 360, 500, Figures 3, 5). More specifically, the first DRA array 2460 is placed within the base portion 2412 of the housing 2410 and the second DRA array 2462 is placed within the sidewall 2422 of the chamber portion 2414 of the device 2400.

Heating chamber 2420 is also located within chamber portion 2414 of housing 2410. FIG. 24 shows a load 2440 within the chamber 2420 (eg, food load or other load). Again, as previously described, the heating chamber 2420 is a closed air chamber that essentially acts as a waveguide with closed ends.

According to one embodiment, the base portion 2412 of the housing 2410 includes a first DRA array 2460 and an electronic substrate 2470 that houses the first microwave power generation module 2450 . Similarly, the chamber portion 2414 of the housing 2410 contains a second DRA array 2462 and an electronic substrate 2472 that houses a second microwave power generation module 2452. The first microwave power generation module 2450 is configured to provide a radio frequency excitation signal to the first DRA array 2460 (eg, through a feed placed in an exciter resonator or through capacitive coupling), which causes the first DRA array 2460 to operate in a A beam of electromagnetic energy is generated in a direction orthogonal to the bottom surface 2424 of the chamber 2420, generally indicated by arrow 2480. Similarly, the second microwave power generation module 2452 is configured to provide radio frequency excitation signals to the second DRA array 2462 (eg, through feeds placed in the exciter resonators or through capacitive coupling), which enables the second DRA array 2462 generates a beam of electromagnetic energy in a direction orthogonal to the chamber sidewall 2422, the direction generally indicated by arrow 2482. As is apparent from Figure 24, the beams of electromagnetic energy generated by the first DRA array 2460 and the second DRA array 2462 have substantially orthogonal orientations. Furthermore, although the first DRA array 2460 and the second DRA array 2462 may operate at substantially the same frequency, they may alternatively operate at different frequencies to provide more broadband energy coupled to the load 2440 within the chamber 2420 .

25 is an illustration of the operation of a microwave system (eg, systems 100, 300, 900, 2400) is a flowchart of the method. In block 2502, the method begins when a system controller (eg, system controller 310, FIG. 3) receives information indicative of parameters to perform a microwave heating operation. For example, information may be derived from user input provided through a user interface (eg, user interface 330, FIG. 3), and the information may convey the duration of the heating operation, the power level of the heating operation, and/or the Other parameters related to the operation.

In block 2504, the system controller causes a power supply (eg, power supply 340, FIG. 1) to provide power to one or more microwave generating modules (eg, module 350, FIG. 3) in a manner that will The microwave generating module is caused to generate one or more excitation signals consistent with the parameters specified for the heating operation.

According to one embodiment, in block 2506, each excitation signal may be delivered to a DRA array (eg, feed 550, FIG. 5) or via a microstrip line (eg, microstrip line 1176, FIG. 11) at block 2506 (eg, feed 550, FIG. 5). , DRA arrays 500, 960, 1060, 1160, 1200, 1300, 1400, 1500, 1600, 1700, 2460). In response, in block 2508, the DRA array generates a beam of directed electromagnetic energy directed toward a heating chamber (eg, heating chamber 920) of the microwave system. As previously discussed, the chamber may contain near-field loads (eg, loads 940, 2440). The DRA array continues to generate directed beams of electromagnetic energy until the supply of the excitation signal is interrupted, at which point the method ends.

26 is a flowchart of a method of fabricating a microwave system (eg, system 100, 300, 900, 2400) including one or more DRA arrays, according to an example embodiment. In block 2602, by combining a plurality of dielectric resonators (eg For example, dielectric resonators 964, 966) are coupled to a DRA substrate (eg, DRA substrate 980) to form a DRA substrate assembly, and the method begins. In the DRA substrate assembly, the distance between the exciter dielectric resonator and the adjacent dielectric resonator ensures that the exciter dielectric resonator and the adjacent dielectric resonator will be closely capacitive in the presence of the excitation signal from the feed coupling (eg, distances less than one-fifth or one-tenth the wavelength of the resonant frequency of the exciter dielectric resonator).

In block 2604, one or more electronic substrates (eg, substrate 970) are mounted into the housing (eg, into a base portion or other portion of the housing). The enclosure includes a heating chamber (eg, chamber 920 ) configured to contain a load (eg, load 940 ) to be heated or thawed. According to one embodiment, each electronic substrate houses a microwave generating module (eg, module 950 ) that includes one or more feed structures (eg, feed 968 or microstrip line 1174 ). Additionally, each electronic substrate includes a ground plane (eg, ground plane 972).

At block 2606, the DRA substrate assembly is mounted in the housing over the electronic substrate such that the DRA substrate is positioned between the ground plane and the heating chamber and the one or more feed structures are sufficiently close to the exciter dielectric resonator (and in possible other dielectric resonators in the array) to be able to excite the resonators to resonate when supplied with a suitable radio frequency excitation signal from the microwave generating module. In block 2608, the DRA array is separated from the chamber (eg, to protect the DRA array) by applying a conformal material (eg, conformal material 1082) over the DRA array, or placing a protective cover (eg, a cover 982) above the DRA array.

For the sake of brevity, resonators, amplifiers, biasing, load modulation, impedance matching, power dividers and/or power combiners, microwave applications, and other functional aspects of the system (as well as the system's) may not be described in detail herein. individual operating components) related conventional techniques. The connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in embodiments of the subject matter. In addition, certain terms may also be used herein for the purpose of reference only, and thus these terms are not intended to be limiting, and the terms "first", "second" refer to structures unless the context clearly dictates otherwise. and other such numerical terms do not imply a sequence or order.

As used herein, "node" means any internal or external reference point, connection point, junction, signal line, etc. at which a given signal, logic level, voltage, data pattern, current or quantity. Furthermore, two or more nodes may be implemented by one physical element (and the two or more signals may be multiplexed, modulated, or otherwise differentiated despite being received or output at a common node).

The above description refers to elements or nodes or features being "connected" or "coupled" together. As used herein, unless expressly stated otherwise, "connected" means that one element is directly joined to (or in direct communication with) another element, and not necessarily mechanically. Similarly, unless expressly stated otherwise, "coupled" means that one element is directly or indirectly joined to (or in direct or indirect communication with) another element, and not necessarily mechanically. Therefore, although the figure The schematic diagrams shown depict one exemplary arrangement of elements, although additional intervening elements, devices, features, or components may be present in the depicted embodiments of the subject matter.

Embodiments of the microwave heating apparatus include: a solid state microwave energy source; a first dielectric resonator antenna including a first exciter dielectric resonator and a first feed structure proximate the first exciter dielectric resonator; and one or a plurality of second dielectric resonators. The first exciter dielectric resonator has a top surface and an opposing bottom surface. The first feed structure is electrically coupled to the microwave energy source to receive the first excitation signal from the microwave energy source. The first exciter dielectric resonator is configured to generate a first electric field in response to an excitation signal provided to the first feed structure. One or more second dielectric resonators are placed within distance of the first exciter dielectric resonator to form a dielectric resonator antenna array. The distances are selected such that each of the second dielectric resonators is tightly capacitively coupled to the first exciter dielectric resonator when the excitation signal is provided.

According to other embodiments, when the excitation signal is provided, the first electric field generated by the first exciter dielectric resonator directly impinges each of the second dielectric resonators such that each of the second dielectric resonators A second electric field is generated in response to the shock of the first electric field. According to yet other embodiments, each of the one or more second dielectric resonators does not directly receive the excitation signal from the feed structure but instead generates the second electric field only in response to the shock of the first electric field Parasitic Dielectric Resonators. According to yet other embodiments, the first exciter dielectric resonator and the second dielectric resonator are arranged in a coplanar configuration such that a portion of the circumferential electric field directly impinges on the second dielectric resonator. According to yet other embodiments, the distance is less than one fifth of the wavelength of the resonant frequency of the first exciter dielectric resonator. According to yet another implementation For example, the distance is between 0 mm and 12.5 mm.

Another embodiment of a microwave heating apparatus includes: a chamber; a solid state microwave energy source; a first dielectric resonator antenna including a first exciter dielectric resonator and a first feed proximate the first exciter dielectric resonator structure; and one or more second dielectric resonators. The chamber is configured to contain a load, and the chamber portion is defined by a first chamber wall having an inner chamber wall surface and an outer chamber wall surface. The first exciter dielectric resonator has a top surface and an opposing bottom surface. The first feed structure is electrically coupled to the microwave energy source to receive a first excitation signal therefrom, and the first exciter dielectric resonator is configured to generate a first electric field in response to the excitation signal provided to the first feed structure. One or more second dielectric resonators are placed within distance of the first exciter dielectric resonator to form a dielectric resonator antenna array. The distances are selected such that each of the second dielectric resonators is tightly capacitively coupled to the first exciter dielectric resonator when the excitation signal is provided.

Embodiments of a method of operating a microwave system including a first microwave generation module include generating, by the first microwave generation module, a first excitation signal for delivery to a first radio frequency (RF) feed structure, wherein the first radio frequency feed structure is proximate to the first Dielectric resonator placement. The method also includes generating, by the first dielectric resonator, a second dielectric resonator that directly impacts a second dielectric resonator that is tightly capacitively coupled to the first dielectric resonator in response to a first excitation signal delivered by the first radio frequency feed structure. first electric field. The method additionally includes generating a second electric field by the second dielectric resonator in response to the shock of the first electric field, wherein the second electric field is directed toward the chamber containing the near-field load.

An embodiment of a method of making a microwave system includes incorporating A first dielectric resonator of a resonant frequency is coupled to the first substrate, and one or more additional dielectric resonators are coupled to the first substrate such that the first dielectric resonator is connected to the one or more additional dielectric resonators The distance between each is tightly capacitively coupled. The first dielectric resonator and the additional dielectric resonators form a dielectric resonator antenna array. The method additionally includes mounting a second substrate into the housing, wherein the radio frequency feed structure is coupled to the second substrate. The housing defines a cavity configured as a waveguide with closed ends. The method additionally includes mounting the first substrate into the housing such that the radio frequency feed structure is sufficiently close to the first dielectric resonator to be able to excite the first dielectric resonator into resonance when the radio frequency feed structure is supplied with a suitable radio frequency excitation signal.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient guide for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which include known equivalents and foreseeable at the time of filing this patent application equivalent of .

100: microwave heating equipment; microwave systems

110: Shell

112: base part

114: Chamber Section

116: Cover

118: External port

120: Heating the chamber

122: Inner side wall

130: Control Panel

140: load

Claims (32)

A microwave heating device, characterized by comprising: a solid state microwave energy source; a first dielectric resonator antenna including a first exciter dielectric resonator and a first feed proximate to the first exciter dielectric resonator structure wherein the first exciter dielectric resonator has a top surface and an opposing bottom surface, wherein the first feed structure is electrically coupled to the microwave energy source to receive a first excitation signal therefrom , and wherein the first exciter dielectric resonator is configured to generate a first electric field in response to the excitation signal provided to the first feed structure; and one or more second dielectric resonators, which phase placed adjacent to a side wall and within a distance of the first exciter dielectric resonator to form a dielectric resonator antenna array, wherein the distance is selected such that the second dielectric resonates when the excitation signal is provided Each of the exciters is tightly capacitively coupled with the first exciter dielectric resonator, and wherein the distance is less than one fifth of the wavelength of the resonant frequency of the first exciter dielectric resonator. The microwave heating apparatus of claim 1, wherein the first electric field generated by the first exciter dielectric resonator directly impacts the second dielectric resonator when the excitation signal is provided each of the second dielectric resonators such that each of the second dielectric resonators generates a second electric field in response to a shock of the first electric field. The microwave heating apparatus of claim 2, wherein each of the one or more second dielectric resonators does not directly receive an excitation signal from a feed structure but instead responds only to the first The impact of an electric field creates a parasitic dielectric resonator of the second electric field. The microwave heating apparatus of claim 1, wherein, when the excitation signal is provided, the first electric field comprises a circumferential electric field, and wherein the first exciter dielectric resonator and the second dielectric The resonators are arranged in a coplanar configuration such that a portion of the circumferential electric field directly impinges on the second dielectric resonator. The microwave heating apparatus of claim 1, wherein the first feed structure includes a feed extending into the first exciter dielectric resonator. The microwave heating apparatus of claim 5, wherein the first dielectric resonator antenna includes one or more additional feeds in the first exciter dielectric resonator, wherein the one or more An additional feed is electrically coupled to the microwave energy source to receive one or more additional excitation signals from the microwave energy source. The microwave heating apparatus of claim 1, wherein the first feed structure includes a conductor aperture coupled to the first exciter dielectric resonator. The microwave heating apparatus of claim 1, wherein the dielectric resonator antenna array further comprises one or more additional dielectric resonator antennas, wherein the one or more additional dielectric resonator antennas Each of the includes an additional exciter dielectric resonator and an additional feed structure proximate the additional exciter dielectric resonator. The microwave heating apparatus of claim 1, wherein the first exciter dielectric resonator and the one or more second dielectric resonators Each of the electrical resonators has a shape selected from the group consisting of a cylinder, a disk, a cone, a parallelepiped, a sphere, and a dome. The microwave heating apparatus of claim 1, wherein the distance is between zero millimeters and 12.5 millimeters. The microwave heating apparatus of claim 1, wherein the distance is less than one tenth of the wavelength of the resonant frequency of the first exciter dielectric resonator. The microwave heating apparatus of claim 1, wherein the distance is between zero millimeters and 3.0 millimeters. The microwave heating apparatus of claim 1, further comprising: a ground plane placed at a first side of the dielectric resonator antenna array; and a cavity placed at the dielectric resonator antenna at the opposite side of the array from the ground plane, wherein the chamber is configured to contain a load. The microwave heating apparatus of claim 13, wherein the cavity would be below a cutoff point in the absence of the dielectric resonator antenna array. The microwave heating apparatus of claim 1, further comprising a substrate having a first side and a second side, wherein the first exciter dielectric resonator and the one or more second dielectric resonators An electrical resonator is physically coupled to the first side of the substrate to maintain a fixed spatial relationship between the first exciter dielectric resonator and the one or more second dielectric resonators. The microwave heating apparatus of claim 15, further comprising a ground plane, wherein the substrate is slidably engaged with the ground plane. The microwave heating apparatus of claim 1, further comprising a conformal material covering the first exciter dielectric resonator and the one or more second dielectric resonators. The microwave heating apparatus of claim 1, wherein the first exciter dielectric resonator and the one or more second dielectric resonators have the same geometry and are the same size. The microwave heating apparatus of claim 1, wherein two or more of the first exciter dielectric resonators and the one or more second dielectric resonators have different geometries. The microwave heating apparatus of claim 1, wherein two or more of the first exciter dielectric resonators and the one or more second dielectric resonators have different sizes. The microwave heating apparatus of claim 1, wherein the number of dielectric resonators in the dielectric resonator antenna array is in the range of two to thirty. The microwave heating apparatus of claim 1, wherein the solid state microwave energy source comprises an amplifier arrangement including a transistor having a transistor input and a transistor output, wherein the amplifier arrangement is configured to The excitation signal is generated at microwave frequencies in the range of 2.3 gigahertz (GHz) to 2.6 GHz. The microwave heating apparatus of claim 22, wherein the amplifier arrangement forms part of an oscillator subsystem, the oscillator subsystem further comprising: a resonant circuit that communicates with the transistor along the transistor output A feedback path between inputs, wherein the resonant frequency of the resonant circuit is the microwave frequency. A microwave heating apparatus, comprising: a chamber configured to contain a load, wherein the chamber portion is defined by a first chamber wall having an inner chamber wall surface and an outer chamber wall surface; a solid state microwave energy source; a first dielectric resonator antenna comprising a first exciter dielectric resonator and a first feed structure proximate the first exciter dielectric resonator, wherein the first exciter dielectric resonator having a top surface and an opposing bottom surface, wherein the first feed structure is electrically coupled to the microwave energy source to receive a first excitation signal therefrom, and wherein the first exciter dielectric resonator configured to generate a first electric field in response to the excitation signal provided to the first feed structure; and one or more second dielectric resonators positioned adjacent to a sidewall and on the first excitation to form a dielectric resonator antenna array, wherein the distance is selected such that each of the second dielectric resonators is in a distance from the first exciter when the excitation signal is provided The electrical resonators are tightly capacitively coupled, and wherein the distance is less than one fifth of the wavelength of the resonant frequency of the first exciter dielectric resonator. The microwave heating device as claimed in claim 24, wherein , the cavity would be below the cutoff point in the absence of the dielectric resonator antenna array. The microwave heating apparatus of claim 24, wherein the cross-sectional shape of the chamber is selected from a circle, an ellipse, and a rectangle. The microwave heating apparatus of claim 24, wherein, when the excitation signal is provided, the first electric field comprises a circumferential electric field, and wherein the first exciter dielectric resonator and the second dielectric The resonators are arranged in a coplanar configuration such that a portion of the circumferential electric field directly impinges on the second dielectric resonator. The microwave heating apparatus of claim 24, wherein the distance is less than one tenth of the wavelength of the resonant frequency of the first exciter dielectric resonator. A method of operating a microwave system including a microwave generation module, the method comprising: generating, by the microwave generation module, a first excitation signal that is transmitted to a first radio frequency (RF) feed structure, wherein the first excitation signal is A radio frequency feed structure is placed proximate to the first dielectric resonator; generation by the first dielectric resonator directly impinges on the second dielectric resonator in response to the first excitation signal transmitted through the first radio frequency feed structure the first electric field, the second dielectric resonator is tightly capacitively coupled to the first dielectric resonator and is placed adjacent to a sidewall and at a wavelength less than the resonant frequency of the first dielectric resonator within one-fifth of the distance; and through the second dielectric resonator in response to the impulse of the first electric field The shock generates a second electric field, wherein the second electric field is directed towards the chamber containing the near-field load. The method of claim 29, further comprising: generating a second excitation signal for delivery to a second radio frequency feed structure, wherein the second radio frequency feed structure is proximate to the first dielectric resonator, the second placing a dielectric resonator or a third dielectric resonator; and generating a third electric field by the first dielectric resonator, the second dielectric resonator or the third dielectric resonator in response to the second excitation signal. The method of claim 30, wherein the first and second excitation signals are generated simultaneously or in stages. The method of claim 30, wherein the first and second excitation signals have substantially the same frequency or different frequencies.

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